Publications
Filter Total Items: 825
Calcareous microfossil-based orbital cyclostratigraphy in the Arctic Ocean
Microfaunal and geochemical proxies from marine sediment records from central Arctic Ocean (CAO) submarine ridges suggest a close relationship over the last 550 thousand years (kyr) between orbital-scale climatic oscillations, sea-ice cover, marine biological productivity and other parameters. Multiple paleoclimate proxies record glacial to interglacial cycles. To understand the climate-cryosphere
Authors
Rachel Marzen, Lauren H. DeNinno, Thomas M. Cronin
Reaction softening by dissolution–precipitation creep in a retrograde greenschist facies ductile shear zone, New Hampshire, USA
We describe strain localization by a mixed process of reaction and microstructural softening in a lower greenschist facies ductile fault zone that transposes and replaces middle to upper amphibolite facies fabrics and mineral assemblages in the host schist of the Littleton Formation near Claremont, New Hampshire. Here, Na-poor muscovite and chlorite progressively replace first staurolite, then gar
Authors
Ryan J. McAleer, David L. Bish, Michael J. Kunk, Karri R. Sicard, Peter M. Valley, Gregory J. Walsh, Bryan A. Wathen, R. P. Wintsch
Digital geologic map data for the Ozark National Scenic Riverways and adjacent areas along the Current River and Jacks Fork, Missouri
The geology of the Ozark National Scenic Riverways (ONSR) in southern Missouri has been mapped at 1:24,000 scale. This endeavor was achieved through the combined efforts of U.S. Geological Survey and Missouri Geological Survey individual quadrangle mapping and additional fieldwork by the authors of this report. Geologic data covering the area of the ONSR and a 1-mile (1.6-kilometer) buffer zone su
Authors
David J. Weary, Randall C. Orndorff, Richard W. Harrison, Robert E. Weems
Holocene climate changes in eastern Beringia (NW North America) – A systematic review of multi-proxy evidence
Reconstructing climates of the past relies on a variety of evidence from a large number of sites to capture the varied features of climate and the spatial heterogeneity of climate change. This review summarizes available information from diverse Holocene paleoenvironmental records across eastern Beringia (Alaska, westernmost Canada and adjacent seas), and it quantifies the primary trends of temper
Authors
Darrell S. Kaufman, Yarrow L. Axford, Andrew C.G. Henderson, Nicolas P. McKay, W. Wyatt Oswald, Casey Saenger, R. Scott Anderson, Hannah L. Bailey, Benjamin Clegg, Konrad Gajewski, Feng Sheng Hu, Miriam C. Jones, Charly Massa, Cody C. Routson, Al Werner, Matthew J. Wooller, Zicheng Yu
Synthesis and revision of the lithostratigraphic groups and formations in the Upper Permian?–Lower Jurassic Newark Supergroup of eastern North America
The Upper Permian? - Lower Jurassic Newark Supergroup of eastern North America has a strikingly uniform succession of lithologic units. This uniformity is seen regardless of whether these units are characterized on the basis of their lithostratigraphy, allostratigraphy, biostratigraphy, or chemostratigraphy. After deposition, these units were broken up tectonically and attacked erosionally; parts
Authors
Robert E. Weems, Lawrence H. Tanner, Spencer G. Lucas
Centimeter-scale surface deformation caused by the 2011 Mineral, Virginia, earthquake sequence at the Carter farm site—Subsidiary structures with a quaternary history
Centimeter-scale ground-surface deformation was produced by the August 23, 2011, magnitude (M) 5.8 earthquake that occurred in Mineral, Virginia. Ground-surface deformation also resulted from the earthquake aftershock sequence. This deformation occurred along a linear northeast-trend near Pendleton, Virginia. It is approximately 10 kilometers (km) northeast of the M5.8 epicenter and near the north
Authors
Richard W. Harrison, J. Stephen Schindler, Milan J. Pavich, J. Wright Horton, Mark W. Carter
Analysis of hydrologic and geochemical time-series data at James Cave, Virginia: Implications for epikarst influence on recharge in Appalachian karst aquifers
The epikarst, which consists of highly weathered rock in the upper vadose zone of exposed karst systems, plays a critical role in determining the hydrologic and geochemical characteristics of recharge to an underlying karst aquifer. This study utilized time series (2007–2014) of hydrologic and geochemical data of drip water collected within James Cave, Virginia, to examine the influence of epikars
Authors
Sarah D. Eagle, William Orndorff, Benjamin F. Schwartz, Daniel H. Doctor, Jonathan D. Gerst, Madeline E. Schreiber
The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction
The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-P
Authors
Harry J. Dowsett, Aisling M. Dolan, David Rowley, Robert Moucha, Alessandro Forte, Jerry X. Mitrovica, Matthew Pound, Ulrich Salzmann, Marci M. Robinson, Mark Chandler, Kevin M. Foley, Alan M. Haywood
The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin
Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present
Authors
Peter J. van Hengstrum, Jeffrey P. Donnelly, Patricia L. Fall, Michael Toomey, Nancy A. Albury, Brian Kakuk
A new specimen of Agorophius pygmaeus (Agorophiidae, Odontoceti, Cetacea) from the Early Oligocene Ashley Formation of South Carolina, USA
The holotype partial skull of Agorophius pygmaeus (the monotypic form for both the genus Agorophius and the Family Agorophiidae) has been missing for approximately 140 years. Since the discovery of Agorophius pygmaeus, many additional taxa and specimens have been placed in the Family Agorophiidae, only to be reclassified and removed later. This has created confusion as to what is and what is not a
Authors
Stephen J. Godfrey, Mark D. Uhen, Jason E. Osborne, Lucy E. Edwards
Geologic evolution of the lower Connecticut River valley: Influence of bedrock geology, glacial deposits, and sea level
This fieldtrip illustrates the character of the lower Connecticut River bedrock valley, in particular its depth, and the lithology and structure of bedrock units it crosses. It examines the character and distribution of the glaciodeltaic terraces that partially fill the valley and discusses the depth of postglacial incision into them.
Authors
Janet Radway Stone, Ralph S. Lewis
Climate change
Climate change (including climate variability) refers to regional or global changes in mean climate state or in patterns of climate variability over decades to millions of years often identified using statistical methods and sometimes referred to as changes in long-term weather conditions (IPCC, 2012). Climate is influenced by changes in continent-ocean configurations due to plate tectonic process
Authors
Thomas M. Cronin